In this process, the tubular film material is usually pulled over the piece item stack without any tension. Afterwards, heat is applied onto the film material, wherein molecular orientations within the film material relax and the film is put in close contact with the contour of the piece item stack. However, the tubular film can equally be stretched elastically to an excessive size and put itself elastically in contact with the contour of the piece item stack during fitting without a separate heat input being required. The device according to the invention and the respective method according to the invention are therefore suitable both for shrinking the tubular film as well as for stretching of said tubular film.
During change of the tubular film stock in the device, the lagging end of the consumed tubular film stock is connected to the leading end of the new tubular film stock. Connected to form a unit in this way, the films of the new and the old tubular film stock are conveyed and fed in the direction onto the cutting device. Said cutting device is operated in the previously known method in a way that the connection area between the leading and the lagging end is separated by the cutting device. Then, it falls into an input area for the piece item stack due to gravity. This separated length section will then have the leading and the lagging end. These two ends are pulled by conveyer rollers of the conveyor device prior to separation with the cutting device so that the new film material does not have to be inserted there.